Computed Tomographic Exploration of the Middle Ethmoidal Artery

Area of Science:

• Otolaryngology
• Vascular Anatomy
• Skull Base Surgery

Background:

• Endonasal vasculature, including ethmoidal arteries, is crucial for sinus and skull base surgeries.
• Anterior ethmoidal artery (AEA) and posterior ethmoidal artery (PEA) are known, but accessory or middle ethmoidal vessels (MEAs) add complexity.

Purpose of the Study:

• To investigate the prevalence and characteristics of accessory or middle ethmoidal vessels (MEAs).
• To inform endonasal surgeons about the potential presence of MEAs in surgical planning.

Main Methods:

• Radiographic study analyzing 50 computed tomographic angiographies.
• Identification of MEAs or their foramina, comparing their locations to AEA and PEA.

Main Results:

• Evidence of MEAs found in 19 out of 50 patients (38%), with 26 arteries identified across 100 sides (26%).
• Unilateral MEAs were more common than bilateral; right-sided prevalence exceeded left-sided.
• No instances of multiple MEAs on a single side were observed.

Conclusions:

• Middle ethmoidal vessels (MEAs) are a significant anatomical variant that endonasal surgeons must recognize.
• Awareness of MEAs is essential for safe surgical navigation in the medial orbit and anterior skull base.